/**
 * Copyright (c) 2011 Technical Centre Radio Systems Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package ua.tcrs.tabula.helpers;

import ua.tcrs.tabula.Event;
import ua.tcrs.tabula.Listener;
import ua.tcrs.tabula.ListenerInterceptor;

public class SafeCastListenerInterceptor<I,O> implements ListenerInterceptor<I,O> {
	Class<I> idType;
	Class<O> bodyType;
	public SafeCastListenerInterceptor( Class<I> idType, Class<O> bodyType ) {
		this.idType = idType;
		this.bodyType = bodyType;
	}
	public Object onEvent( Listener<I,O> target, Event<I,O> event ) {
		if ( event.getId() != null && !idType.isInstance( event.getId() ) ) return null;
		if ( event.getBody() != null && !idType.isInstance( event.getBody() ) ) return null;
		return target.onEvent( event );
	}
}
